1. Technical Field
This disclosure relates generally to the field of optics, and in particular but not exclusively, relates to contact lenses.
2. Background Art
Accommodation is a process by which the eye adjusts its focal distance to maintain focus on objects of varying distance. Accommodation is a reflex action, but can be consciously manipulated. Accommodation is controlled by contractions of the ciliary muscle. The ciliary muscle encircles the eye's elastic lens and applies a force on the elastic lens during muscle contractions that change the focal point of the elastic lens.
As an individual ages, the effectiveness of the ciliary muscle can degrade due to Presbyopia or other progressive age-related conditions affecting the focusing strength of the eye. Recent technologies have begun to provide for various devices that operate in or on a human eye to aid the visual focus of a user. For one type of these devices, an accommodating lens includes one or more liquid crystal elements and circuitry to apply an electrical current to change the index of refraction of the one or more elements.
However, the need to drive and control these liquid crystal elements results in significant power consumption during operation of such devices. The liquid crystal elements often have to be driven with signals having peak-to-peak voltage on the order of 5 Volts (V), and even up to 10V. Due to such power loads, users of the devices are required to frequently replace lens devices and/or to frequently recharge batteries operating the lens devices. Such requirements limit the ability of users to conveniently use these and other types of accommodating eye-mountable devices.